This was a paperback science fiction novel which I checked out from a public library in Indiana in the mid-1980s.
The text on the back cover was what originally caught my eye. It said something to the effect that one day a talented artist got the sad news that he had developed a nasty medical condition which might let him live another twenty years if he took very good care of himself and stayed on the planet where he currently resided . . . or he could work to fulfill his dream of traveling to other worlds, but lots of interstellar travel would so aggravate his condition that he would probably die after about one year of it. Then the final sentence on the back cover said approximately the following:
This is the story of that year.
Beyond that premise, I only remember details of one scene. The artist, and some other human traders or explorers, are trapped in a holy shrine on a planet inhabited by a nonhuman species. The original plan had been to sneak in and steal some of the sacred items stored within. But now they are besieged by hostile natives who feel this intrusion is sacrilegious -- and even if the explorers negotiate safe passage to get back to their ship and leave quietly, they certainly won't be allowed to take the sacred items with them. The artist suggests he'll spend the next few hours making detailed sketches of these items, and they ought to be able to sell those exclusive sketches to wealthy collectors back home -- for enough money to at least make a small profit on this trip.